Official

If you twist the faucet, water will come out at any time, but where does the water we drink come from?
On the homepage of the Tokyo Waterworks Bureau, "Water Distribution System-Home Tap Water Information", select the ward city name, town name, and chome and press the search button to display the water purification plant that mainly distributes water. There is a function.

Let's try it.
When I entered the name of the town in Chuo-ku, I found the following facts.

The area west of the Sumida River in Chuo-ku is mainly supplied from the Asaka Water Purification Plant. Water intake from Arakawa. Arakawa is also led by a lot of water from the Tone River through the Musashi Channel.
The Asaka Water Purification Plant is the largest water purification plant in Tokyo, with a processing capacity of 1.7 million cubic meters / day, accounting for 1/4 of the total processing capacity of the Tokyo Waterworks Bureau. The Asaka Water Purification Plant is located in Asaka City, Saitama Prefecture, not in Tokyo. A raw water contact pipe has been installed between the Higashimurayama Water Purification Plant, and in addition to the water of the Tone River and Arakawa, water from the Tama River can be used.

The area east of the Sumida River in Chuo-ku is mainly supplied from Kanamachijosuijo. Water intake from Edogawa (Tone River water system).
Kanamachijosuijo is the second largest water purification plant in the capital with a processing capacity of 1.5 million cubic meters / day, accounting for 1/5 of the total processing capacity of the Tokyo Metropolitan Waterworks Bureau.

During the Edo period, water was distributed to the city of Edo through Kanda Josui and Tamagawajosui. With the progress of urbanization in Tokyo, dependent water systems have changed, and water exchanges have begun to take place over a wider area. Dams and rivers in various parts of the Kanto region support drinking water in Tokyo.

You want to use water carefully.